1. Field of the Invention
The present invention relates to a user-host-computer system comprising at least two user computers or so-called clients and at least one host computer connectable to each of said user computers by a data network like an Intranet or the Internet. Each of said host computers runs a virtualization program for virtualizing a plurality of operating systems, the so-called guests.
2. Background Art
In the prior art the aforesaid basic computer system structure is known in which multiple users are able to log-on to each guest which such is a multi-user-operating-system. Moreover, single-user-operating-systems are state of the art in which under one operating system only one user or client at a time is supported.
Running multiple single-user-operating-systems on host-computers in the computer-center and connecting clients running certain types of terminal emulations has several advantages:                less administration complexity as all data and applications are hosted in the data center        applications do not need to fulfill certain requirements which are the fact on multi-user-operating-systems (terminal servers)        data and applications are totally independent for each user compared to terminal servers where only one common operating-system is running        cost savings because there is no need to have hardware and software resources for each single user as normally not all users access the computer-center at the same time.        
In user-host-computer systems in which several guest operating systems are participating there is the general problem to assign an user to a specific currently unused guest and to avoid an unbalanced load of the host computers to enhance the efficiency of the system.